Electrical Charge Mr. Fleming

Standard 9.2: The electrical force is a universal force that exists between any two charged objects.

Expected Performances D4. Explain the relationship among voltage, current and resistance in a simple series circuit. D5. Explain how electricity is used to produce heat and light in incandescent bulbs and heating elements. D6. Describe the relationship between current and magnetism.

Essential Question What is electricity and how does it move within an object?

Electricity Electricity: energy due to the movement of electrons through a material. Protons stay put Discovered by Ben Franklin.  

Charged vs Uncharged All objects are made of atoms Not Charged Charged Contain electrons, protons, and neutrons. Not Charged Objects charge= # of protons - # of electrons Objects that have an equal amount of electrons and protons Charged Objects can be negatively charged or positively charged. Positively Charged=more protons than electrons Negatively Charged=more electrons than protons

Two types of electricity Static electricity: electricity involving a build-up of stationary charges. Current electricity: electricity involving the flow of e- through a material.

Static Electricity The accumulation of excess electrical charge on an object. To create static electricity: Electrons are transferred between materials By friction/rubbing causing one material to build up an excess of electrons Second material ends up with a shortage of electrons.

Static Electricity

Static Electricity - charge = material with excess of electrons + charge= material with shortage of electrons If the difference in charges becomes large enough the electrons jump from – to + creating a spark (lightning)

Static Electricity Recall What does electricity represent: The movement of protons. The movement of neutrons. The movement of electrons. All of the Above Movement of Electrons

Static Electricity Recall What causes a spark or lightening to happen? Two objects that have an equal distribution of positive and negative charges. Two objects that are only positively charged. When two objects build-up a difference in charge between each other. Two objects that are negatively charged. c. When two object build-up a difference in charge between each other.

Static Electricity Demo Balloons

Law of charges: Like charges repel, unlike charges attract. “Likes repel. Opposites attract.”

Law of Conservation of Charge Electrical events simply rearrange the charges or move them from one object to another object Total charge= positive + negative charges within universe is 0.

Law of Conservation of Charge

Electric Fields Charged objects are surrounded by an electrical field that is similar to magnetic fields. Electrical Field – a force exerted by a charged object.

Electric Fields

Conductors and Insulators A material in which electrons are able to move easily.

Conductors & Insulators A material in which electrons are not able to move freely.

Charging Objects Static charges are not noticed until something interacts with their field or they move by: Charging by Contact or Conduction Rub two material together results in transfer of electrons. One object has positive charge One object has negative charge OBJECTS TOUCH

Charging Objects: Conduction

Charging Objects: Induction Charging by Induction The rearrangement of electrons on a neutral object. Caused by presence of other object’s electric field. Objects DO NOT TOUCH.

Charging Objects: Induction

Electrical Charge Choose TRUE or FALSE 1. T or F. Opposite charges DO NOT attract each other. False 2. T or F. All charged objects have electrical fields? True

Electrical Charge Recall 3. An insulator is: A. Good at keeping heat in or out. B. Make it easy for electrons to pass through. C. Make it hard for electrons to pass through. D. Both A & C

Electrical Charge Recall What is the difference between conduction and induction? A. One involves the movement of protons instead of elections B. One does not change the arrangement of electrons. C. Conduction is the rearrangement of electrons by touch while induction is rearrangement without touch.